RESUMO
We recently found that the G protein coupled receptor GPR101 mediates the phagocyte-directed pro-resolving activities of RvD5n-3 DPA (n-3 docosapentaenoic acid-derived Resolvin D5). Herein, we investigated the endogenous role of this pro-resolving receptor in modulating macrophage biology using a novel mouse line where the expression of Gpr101 was conditionally deleted in macrophages (MacGpr101KO). Peritoneal macrophages obtained from naïve MacGpr101KO mice displayed a marked shift in the expression of phenotypic and activation markers, including the Interleukin (IL)-10 and IL-23 receptors. Loss of Gpr101 on macrophages was also associated with a significant disruption in their cellular metabolism and a decreased ability to migrate towards the chemoattractant Mcp-1. The alterations in macrophage phenotype observed in Gpr101 deficient macrophages were maintained following inflammatory challenge. This was linked with an increased inflammatory response in the Gpr101 deficient animals and a reduced ability of phagocytes, including macrophages, to clear bacteria. Loss of Gpr101 on macrophages disrupted host pro-resolving responses to zymosan challenge with MacGpr101KO mice exhibiting significantly higher neutrophil numbers and a delay in the resolution interval when compared with control mice. These observations were linked with a marked dysregulation in peritoneal lipid mediator concentrations in Gpr101 deficient mice, with a downregulation of pro-resolving mediators including MaR2n-3 DPA, Resolvin (Rv) D3 and RvE3. Together these findings identify Gpr101 as a novel regulator of both macrophage phenotype and function, modulating key biological activities in both limiting the propagation of inflammation and expediting its resolution.
Assuntos
Inflamação , Macrófagos , Receptores Acoplados a Proteínas G , Animais , Camundongos , Ácidos Docosa-Hexaenoicos/farmacologia , Ácidos Docosa-Hexaenoicos/metabolismo , Imunidade , Macrófagos/metabolismo , Fenótipo , Receptores Acoplados a Proteínas G/genéticaRESUMO
El manejo del adenocarcinoma de recto se ha visto revolucionado por la cirugía mesorectal y la neoadyuvancia al igual que el cáncer epidermoide de ano con el protocolo de Nigro. Sin embargo, los adenocarcinomas de ano constituyen una patología infrecuente, relacionada con procesos inflamatorios crónicos como las fístulas perianales y cuyo tratamiento genera controversias. El desconocimiento de sus características clínicas e imagenológicas puede generar una confusión diagnóstica principalmente con un absceso perianal. Presentamos el caso clínico de un adenocarcinoma de canal anal en relación a una fístula perianal crónica y una revisión de la literatura actual sobre el tema.
The mesorectal surgery and the neoadyuvant treatment have changed the management of rectal adenocarcinoma. The Nigro protocol had the same impact on the squamous cell cancer of the anus. However, the adenocarcinoma of the anus is an infrequent pathology, related to chronic inflammatory processes such as perianal fistulas and its treatment generates controversy. The lack of knowledge about clinical and imaging characteristics of this pathology can lead to diagnostic confusion, mainly with a perianal abscess. We hereby present the clinical case of an anal canal adenocarcinoma in relation to a chronic perianal fistula and a review of the current literature on the subject.
O manejo do adenocarcinoma retal foi revolucionado pela cirurgia mesorretal e pelo tratamento neoadjuvante, assim como o câncer de células escamosas do ânus com o protocolo Nigro. Entretanto, os adenocarcinomas do ânus são uma patologia pouco frequente, relacionada a processos inflamatórios crônicos como as fístulas perianais e cujo tratamento gera controvérsias. O desconhecimento de suas características clínicas e de imagem pode levar a uma confusão diagnóstica, principalmente com o abscesso perianal. Apresentamos o caso clínico de um adenocarcinoma do canal anal relacionado a uma fístula perianal crônica e uma revisão da literatura atual sobre o assunto.
Assuntos
Humanos , Masculino , Idoso , Canal Anal/patologia , Neoplasias do Ânus/diagnóstico por imagem , Adenocarcinoma Mucinoso/diagnóstico por imagem , Neoplasias do Ânus/radioterapia , Cuidados Paliativos , Fístula Retal , Evolução Fatal , Adenocarcinoma Mucinoso/radioterapiaRESUMO
La endocarditis infecciosa es una patología heterogénea con una alta mortalidad y requiere tratamiento quirúrgico en al menos la mitad de los casos. Cuando asienta en posición mitral, la reparación valvular en lugar de su sustitución, si bien representa un desafío técnico, ha ido ganando terreno en los últimos años. Describimos el caso de un paciente que se presentó con una endocarditis sobre válvula nativa mitral en quien se realizó una plastia valvular exitosa. Revisaremos la evidencia acerca de su beneficio.
Infective endocarditis is a heterogeneous disease with a high mortality and that requires surgical treatment in at least half of cases. When seated in mitral position, valve repair rather than replacement, while technically challenging, has been gaining popularity in recent years. We describe the case of a patient who presented with a mitral valve endocarditis in whom a successful valve repair was performed. Evidence supporting its use will be reviewed.
A endocardite infecciosa é uma doença heterogênea com alta mortalidade que requer tratamento cirúrgico em pelo menos metade dos casos. Quando sentado na posição mitral, o reparo da válvula, em vez da substituição da válvula, embora seja um desafio técnico, tem ganhado espaço nos últimos anos. Descrevemos o caso de um paciente que apresentou endocardite valvar mitral nativa, no qual foi realizada plastia valvar com sucesso. Vamos revisar as evidências sobre o seu benefício.
Assuntos
Humanos , Masculino , Adulto , Infecções Estafilocócicas/cirurgia , Endocardite Bacteriana/cirurgia , Insuficiência da Valva Mitral/cirurgia , Infecções Estafilocócicas/complicações , Infecções Estafilocócicas/diagnóstico , Infecções Estafilocócicas/tratamento farmacológico , Cefazolina/uso terapêutico , Endocardite Bacteriana/tratamento farmacológico , Endocardite Bacteriana/diagnóstico por imagem , Antibacterianos/uso terapêutico , Insuficiência da Valva Mitral/microbiologia , Insuficiência da Valva Mitral/tratamento farmacológico , Insuficiência da Valva Mitral/diagnóstico por imagemRESUMO
El término miocarditis hace referencia a una inflamación del miocardio, que puede tener diversas causas (infecciones, tóxicos, enfermedades autoinmunes). Su diagnóstico es desafiante debido al gran espectro de presentaciones clínicas que puede adoptar, muchas veces imitando patologías más prevalentes como el infarto agudo de miocardio. La miocarditis asociada a enfermedades autoinmunes es poco frecuente, y la importancia de reconocerla radica en que el diagnóstico e inicio temprano del tratamiento son cruciales para mejorar su pronóstico. Presentamos aquí un caso clínico de una perimiocarditis lúpica.
Myocarditis refers to an inflammation of the myocardium, which can have various causes (infections, toxic substances, autoimmune diseases). Its diagnosis is challenging due to the wide spectrum of clinical presentations, often mimicking more prevalent pathologies such as acute myocardial infarction. Myocarditis associated with autoimmune diseases is rare, and the importance of recognizing is that early diagnosis and initiation of treatment are crucial to improve its prognosis. We present here a clinical case of lupus perimyocarditis.
O termo miocardite refere-se a uma inflamação do miocárdio, que pode ter várias causas (infecções, substâncias tóxicas, doenças autoimunes). Seu diagnóstico é desafiador devido ao amplo espectro de apresentações clínicas que pode ter, muitas vezes mimetizando patologias mais prevalentes como o infarto agudo do miocárdio. A miocardite associada a doenças autoimunes é rara, e a importância de reconhecê-la reside no fato de que o diagnóstico precoce e o início do tratamento são cruciais para melhorar seu prognóstico. Apresentamos aqui um caso clínico de perimiocardite lúpica.
Assuntos
Humanos , Feminino , Adulto , Insuficiência Cardíaca/terapia , Miocardite/diagnóstico por imagem , Dor no Peito , Metilprednisolona/uso terapêutico , Resultado do Tratamento , Imunoglobulinas Intravenosas/uso terapêutico , Ciclofosfamida/uso terapêutico , Hidroxicloroquina/uso terapêutico , Fatores Imunológicos/uso terapêutico , Imunossupressores/uso terapêutico , Lúpus Eritematoso Sistêmico/complicações , Miocardite/etiologia , Miocardite/tratamento farmacológicoRESUMO
Inflammation is linked with carcinogenesis in many types of cancer including colorectal cancer (CRC). Aspirin is recommended for the prevention of CRC, although the mechanism(s) mediating its immunomodulatory actions remain incompletely understood. Here, we demonstrate that aspirin increased concentrations of the immune-regulatory aspirin-triggered specialized proresolving mediators (AT-SPMs), including AT-lipoxin A4 and AT-resolvin D1, in colonic tissues during inflammation-associated CRC (I-CRC). Aspirin also down-regulated the expression of the checkpoint protein programmed cell death protein-1 in macrophages and CD8+ T cells from the colonic mucosa. Inhibition of AT-SPM biosynthesis or knockout of the AT-SPM receptor Alx/Fpr2 reversed the immunomodulatory actions of aspirin on macrophages and CD8+ T cells and abrogated its protective effects during I-CRC. Furthermore, treatment of mice with AT-SPM recapitulated the immune-directed actions of aspirin during I-CRC. Together, these findings elucidate a central role for AT-SPM in mediating the immune-directed actions of aspirin in regulating I-CRC progression.
Assuntos
Aspirina , Neoplasias Associadas a Colite , Animais , Aspirina/farmacologia , Aspirina/uso terapêutico , Linfócitos T CD8-Positivos/metabolismo , Inflamação/metabolismo , Macrófagos/metabolismo , Camundongos , Receptores de Formil Peptídeo/metabolismoRESUMO
Justification: Breastfeeding provides the best infant food, and closeness to the mother is crucial for successful breastfeeding. However, sharing parents' beds and sleeping on the stomach poses a high risk for sudden infant death syndrome (SIDS). There is little information on these practices regarding the Spanish population. Objective: To explore breastfeeding and bed-sharing practices in the study population Materials and Methods: A cross sectional observational study was conducted through an anonymous telephone survey with a representative random sample of babies born in the Health Area of La Marina Baixa, Alicante, between 2018 and 2019. A previous-day strategy was implemented to determine the feeding and bed-sharing variables. Results: The total breastfeeding and formula-feeding rates were 47.0% and 52.9%, respectively. The overall bed-sharing rate was 66.5%. The breastfeeding rate was 86.4% with bed-sharing and 13.6% without bed-sharing. The rate of prone sleeping position in children younger than 6 months of age was 9.3-3.5% with breastfeeding and 5.8% with formula feeding. Lower frequencies of tobacco, alcohol, and nonsupine sleeping positions were observed among mothers who practiced breastfeeding and bed-sharing. Conclusions: We found a close relationship between breastfeeding and bed-sharing and a lower frequency of SIDS risk factors associated with both practices. Families should be informed about the risk factors associated with SIDS to encourage safe bed-sharing while avoiding recommendations that discourage breastfeeding.
Assuntos
Morte Súbita do Lactente , Aleitamento Materno , Criança , Estudos Transversais , Feminino , Humanos , Lactente , Cuidado do Lactente , Decúbito Ventral , Fatores de Risco , Sono , Morte Súbita do Lactente/epidemiologia , Morte Súbita do Lactente/etiologia , Morte Súbita do Lactente/prevenção & controleRESUMO
The migration of neutrophils from the blood circulation to sites of infection or injury is a key immune response and requires the breaching of endothelial cells (ECs) that line the inner aspect of blood vessels. Unregulated neutrophil transendothelial cell migration (TEM) is pathogenic, but the molecular basis of its physiological termination remains unknown. Here, we demonstrated that ECs of venules in inflamed tissues exhibited a robust autophagic response that was aligned temporally with the peak of neutrophil trafficking and was strictly localized to EC contacts. Genetic ablation of EC autophagy led to excessive neutrophil TEM and uncontrolled leukocyte migration in murine inflammatory models, while pharmacological induction of autophagy suppressed neutrophil infiltration into tissues. Mechanistically, autophagy regulated the remodeling of EC junctions and expression of key EC adhesion molecules, facilitating their intracellular trafficking and degradation. Collectively, we have identified autophagy as a modulator of EC leukocyte trafficking machinery aimed at terminating physiological inflammation.
Assuntos
Autofagia/fisiologia , Células Endoteliais/fisiologia , Infiltração de Neutrófilos/fisiologia , Migração Transendotelial e Transepitelial/fisiologia , Animais , Quimiotaxia de Leucócito/fisiologia , Células Endoteliais/patologia , Células Endoteliais da Veia Umbilical Humana/imunologia , Células Endoteliais da Veia Umbilical Humana/patologia , Humanos , Inflamação/imunologia , Inflamação/patologia , Junções Intercelulares/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Neutrófilos/fisiologiaRESUMO
[Figure: see text].
Assuntos
COVID-19/sangue , COVID-19/imunologia , Mediadores da Inflamação/sangue , Mediadores da Inflamação/imunologia , Fagócitos/imunologia , Células Cultivadas , Humanos , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/virologia , Neutrófilos/imunologia , Neutrófilos/virologia , Fagócitos/virologiaRESUMO
Regulatory T-cells (Tregs) are central in the maintenance of homeostasis and resolution of inflammation. However, the mechanisms that govern their differentiation and function are not completely understood. Herein, we demonstrate a central role for the lipid mediator biosynthetic enzyme 15-lipoxygenase (ALOX15) in regulating key aspects of Treg biology. Pharmacological inhibition or genetic deletion of ALOX15 in Tregs decreased FOXP3 expression, altered Treg transcriptional profile and shifted their metabolism. This was linked with an impaired ability of Alox15-deficient cells to exert their pro-resolving actions, including a decrease in their ability to upregulate macrophage efferocytosis and a downregulation of interferon gamma expression in Th1 cells. Incubation of Tregs with the ALOX15-derived specilized pro-resolving mediators (SPM)s Resolvin (Rv)D3 and RvD5n-3 DPA rescued FOXP3 expression in cells where ALOX15 activity was inhibited. In vivo, deletion of Alox15 led to increased vascular lipid load and expansion of Th1 cells in mice fed western diet, a phenomenon that was reversed when Alox15-deficient mice were reconstituted with wild type Tregs. Taken together these findings demonstrate a central role of pro-resolving lipid mediators in governing the differentiation of naive T-cells to Tregs.
Assuntos
Araquidonato 15-Lipoxigenase/metabolismo , Linfócitos T Reguladores/metabolismo , Animais , Diferenciação Celular , Voluntários Saudáveis , Humanos , Masculino , Camundongos , Regulação para CimaRESUMO
Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare cytotoxic cutaneous lymphoma. Differential diagnosis with lupus erythematosus panniculitis (LEP) can be challenging and overlapping cases have been described. In this study, we investigate whether gene expression profiling may or not identify markers that can be used to improve our understanding of the disease and to make a precise differential diagnosis. SPTCL, LEP, and overlapping cases were analyzed using a customized NanoString platform including 208 genes related to T-cell differentiation, stromal signatures, oncogenes, and tumor suppressor genes. Gene expression unsupervised analysis of the samples differentiated SPTCL from LEP samples. Most overlapping cases were clustered with LEP cases. Differentially expressed genes were observed when comparing SPTCL with LEP cases; and overlapping with LEP cases. Gene set enrichment analysis recognized gene sets defining each group. In conclusion, SPTCL and LEP have distinctive molecular profiles and the molecular background of overlapping cases more closely resembles LEP.
Assuntos
Linfoma de Células T , Paniculite de Lúpus Eritematoso , Paniculite , Diagnóstico Diferencial , Humanos , Imuno-Histoquímica , Linfoma de Células T/diagnóstico , Linfoma de Células T/genética , Paniculite/diagnóstico , Paniculite/genética , Paniculite de Lúpus Eritematoso/diagnóstico , Paniculite de Lúpus Eritematoso/genéticaRESUMO
The photolysis at 254 nm of lithium iodide and olefins 1 carrying an electron-withdrawing Z-substituent in CO2-saturated (1 bar) anhydrous acetonitrile at room temperature produces the atom efficient and transition metal-free photoiodocarboxylation of the CâC double bond. The reaction proceeds well for terminal olefins 1 to form the new C-I and C-C σ-bonds at the α and ß-positions of the Z-substituent, respectively, and is strongly inhibited by polar protic solvents or additives. The experimental results suggest that the reaction channels through the radical anion [CO2â¢-] in acetonitrile, yet involves different intermediates in aqueous medium. The stabilizing ion-quadrupole and electron donor-acceptor interactions of CO2 with the iodide anion play a crucial role in the reaction course as they allow CO2 to penetrate the solvation shell of the anion in acetonitrile, but not in water. The reaction paths and the reactive intermediates involved under different conditions are discussed.
RESUMO
The photolysis of triethylamine (1a) in the presence of carbon dioxide leads to the hydrogenation of CO2, the α-C-C coupling of 1a, and the CO2 insertion into the α-C-H σ-bond of amine 1a. This reaction is proposed to proceed through the radical ion pair [R3Nâ¢+·CO2â¢-] generated by the photoionization of amine 1a and the electron capture by CO2. The presence of lithium tetrafluoroborate in the reaction medium promotes the efficient and stereoselective α-C-C coupling of 1a by enhancing the production of α-dialkylamino radicals and the isomerization of N,N,N',N'-tetraethylbutane-2,3-diamine (4a).
RESUMO
Lithium ß-ketocarboxylates 1(COOLi), prepared by the reaction of lithium enolates 2(Li+) with carbon dioxide, readily undergo decarboxylative disproportionation in THF solution unless in the presence of lithium salts, in which case they are indefinitely stable at room temperature in inert atmosphere. The availability of stable THF solutions of lithium ß-ketocarboxylates 1(COOLi) in the absence of carbon dioxide allowed reactions to take place with nitrogen bases and alkyl halides 3 to give α-alkyl ketones 1(R) after acidic hydrolysis. The sequence thus represents the use of carbon dioxide as a removable directing group for the selective monoalkylation of lithium enolates 2(Li+). The roles of lithium salts in preventing the disproportionation of lithium ß-ketocarboxylates 1(COOLi) and in determining the course of the reaction with bases and alkyl halides 3 are discussed.
RESUMO
The photolysis of iodide anions promotes the reaction of carbon dioxide with hydrogen sulfide or thiols to quantitatively yield formic acid and sulfur or disulfides. The reaction proceeds in acetonitrile and aqueous solutions, at atmospheric pressure and room temperature by irradiation using a low-pressure mercury lamp. This transition-metal-free photocatalytic process for CO2 capture coupled with H2 S removal may have been relevant as a prebiotic carbon dioxide fixation.
Assuntos
Dióxido de Carbono/química , Formiatos/química , Sulfeto de Hidrogênio/química , Iodetos/química , Processos Fotoquímicos , Compostos de Sulfidrila/química , Catálise , OxirreduçãoRESUMO
Ethanol () inhibits SN1 reactions of alkyl halides in supercritical carbon dioxide (scCO2) and gives no ethers as products. The unexpected behaviour of alcohols in the reaction of alkyl halides with 1,3-dimethoxybenzene () in scCO2 under different conditions is rationalised in terms of Brønsted and Lewis acid-base equilibria of reagents, intermediates, additives and products in a singular solvent characterised by: (i) the strong quadrupole and Lewis acid character of carbon dioxide, which hinders SN2 paths by strongly solvating basic solutes; (ii) the weak Lewis base character of carbon dioxide, which prevents it from behaving as a proton sink; (iii) the compressible nature of scCO2, which enhances the impact of preferential solvation on carbon dioxide availability for the solvent-demanding rate determining step.
RESUMO
The understanding of renal fibrosis in chronic kidney disease (CKD) remains as a challenge. More than 10% of the population of developed countries suffer from CKD. Proliferation and activation of myofibroblasts and accumulation of extracellular matrix proteins are the main features of kidney fibrosis, a process in which a large number of cytokines are involved. Targeting cytokines responsible for kidney fibrosis development might be an important strategy to face the problem of CKD. The increasing knowledge of the signaling pathway network of the transforming growth factor beta (TGF-ß) superfamily members, such as the profibrotic cytokine TGF-ß1 or the bone morphogenetic proteins (BMPs), and their involvement in the regulation of kidney fibrosis, has stimulated numerous research teams to look for potential strategies to inhibit profibrotic cytokines or to enhance the anti-fibrotic actions of other cytokines. The consequence of all these studies is a better understanding of all these canonical (Smad-mediated) and non-canonical signaling pathways. In addition, the different receptors involved for signaling of each cytokine, the different combinations of type I-type II receptors, and the presence and function of co-receptors that can influence the biological response have been also described. However, are these studies leading to suitable strategies to block the appearance and progression of kidney fibrosis? In this review, we offer a critical perspective analyzing the achievements using the most important strategies developed up till now: TGF-ß antibodies, chemical inhibitors of TGF-ß receptors, miRNAs and signaling pathways and BMP agonists with a potential role as therapeutic molecules against kidney fibrosis.
Assuntos
Proteínas Morfogenéticas Ósseas/metabolismo , Rim/patologia , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Insuficiência Renal Crônica/patologia , Fator de Crescimento Transformador beta1/metabolismo , Proteínas Morfogenéticas Ósseas/agonistas , Proteínas Morfogenéticas Ósseas/antagonistas & inibidores , Citocinas/metabolismo , Fibrose , Humanos , MicroRNAs , Receptores de Fatores de Crescimento Transformadores beta/antagonistas & inibidores , Transdução de Sinais , Proteínas Smad/metabolismo , Fator de Crescimento Transformador beta1/antagonistas & inibidoresRESUMO
The activin receptor-like kinase 1 (ALK-1) is a type I cell-surface receptor for the transforming growth factor-ß (TGF-ß) family of proteins. Hypertension is related to TGF-ß1, because increased TGF-ß1 expression is correlated with an elevation in arterial pressure (AP) and TGF-ß expression is upregulated by the renin-angiotensin-aldosterone system. The purpose of this study was to assess the role of ALK-1 in regulation of AP using Alk1 haploinsufficient mice (Alk1(+/-)). We observed that systolic and diastolic AP were significantly higher in Alk1(+/-) than in Alk1(+/+) mice, and all functional and structural cardiac parameters (echocardiography and electrocardiography) were similar in both groups. Alk1(+/-) mice showed alterations in the circadian rhythm of AP, with higher AP than Alk1(+/+) mice during most of the light period. Higher AP in Alk1(+/-) mice is not a result of a reduction in the NO-dependent vasodilator response or of overactivation of the peripheral renin-angiotensin system. However, intracerebroventricular administration of losartan had a hypotensive effect in Alk1(+/-) and not in Alk1(+/+) mice. Alk1(+/-) mice showed a greater hypotensive response to the ß-adrenergic antagonist atenolol and higher concentrations of epinephrine and norepinephrine in plasma than Alk1(+/+) mice. The number of brain cholinergic neurons in the anterior basal forebrain was reduced in Alk1(+/-) mice. Thus, we concluded that the ALK-1 receptor is involved in the control of AP, and the high AP of Alk1(+/-) mice is explained mainly by the sympathetic overactivation shown by these animals, which is probably related to the decreased number of cholinergic neurons.
Assuntos
Receptores de Ativinas Tipo I/deficiência , Pressão Arterial , Heterozigoto , Hipertensão/enzimologia , Receptores de Ativinas Tipo I/genética , Receptores de Activinas Tipo II , Bloqueadores do Receptor Tipo 1 de Angiotensina II/farmacologia , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Animais , Anti-Hipertensivos/farmacologia , Pressão Arterial/efeitos dos fármacos , Pressão Arterial/genética , Sistema Nervoso Central/patologia , Sistema Nervoso Central/fisiopatologia , Neurônios Colinérgicos/patologia , Ritmo Circadiano , Relação Dose-Resposta a Droga , Predisposição Genética para Doença , Haploinsuficiência , Hipertensão/tratamento farmacológico , Hipertensão/genética , Hipertensão/patologia , Hipertensão/fisiopatologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fenótipo , Sistema Renina-Angiotensina/efeitos dos fármacos , Sistema Nervoso Simpático/enzimologia , Sistema Nervoso Simpático/fisiopatologia , Fatores de Tempo , Vasoconstrição/efeitos dos fármacos , Vasoconstritores/farmacologia , Vasodilatação/efeitos dos fármacos , Vasodilatadores/farmacologiaRESUMO
Transforming growth factor-ß (TGF-ß) plays a pivotal role in renal fibrosis. Endoglin, a 180 KDa membrane glycoprotein, is a TGF-ß co-receptor overexpressed in several models of chronic kidney disease, but its function in renal fibrosis remains uncertain. Two membrane isoforms generated by alternative splicing have been described, L-Endoglin (long) and S-Endoglin (short) that differ from each other in their cytoplasmic tails, being L-Endoglin the most abundant isoform. The aim of this study was to assess the effect of L-Endoglin overexpression in renal tubulo-interstitial fibrosis. For this purpose, a transgenic mouse which ubiquitously overexpresses human L-Endoglin (L-ENG+) was generated and unilateral ureteral obstruction (UUO) was performed in L-ENG+ mice and their wild type (WT) littermates. Obstructed kidneys from L-ENG+ mice showed higher amounts of type I collagen and fibronectin but similar levels of α-smooth muscle actin (α-SMA) than obstructed kidneys from WT mice. Smad1 and Smad3 phosphorylation were significantly higher in obstructed kidneys from L-ENG+ than in WT mice. Our results suggest that the higher increase of renal fibrosis observed in L-ENG+ mice is not due to a major abundance of myofibroblasts, as similar levels of α-SMA were observed in both L-ENG+ and WT mice, but to the higher collagen and fibronectin synthesis by these fibroblasts. Furthermore, in vivo L-Endoglin overexpression potentiates Smad1 and Smad3 pathways and this effect is associated with higher renal fibrosis development.
Assuntos
Antígenos CD/genética , Expressão Gênica , Nefropatias/etiologia , Nefropatias/patologia , Receptores de Superfície Celular/genética , Obstrução Ureteral/complicações , Animais , Colágeno/metabolismo , Modelos Animais de Doenças , Endoglina , Matriz Extracelular/metabolismo , Fibronectinas , Fibrose , Humanos , Nefropatias/metabolismo , Camundongos , Camundongos Transgênicos , Miofibroblastos/metabolismo , Miofibroblastos/patologia , Transdução de Sinais/efeitos dos fármacos , Proteínas Smad/metabolismo , Fator de Crescimento Transformador beta/metabolismoRESUMO
The rate constants for the epoxidation of cis-2-heptene with [2-percarboxyethyl]-functionalized silica (1a) and meta-chloroperbenzoic acid (mCPBA) (1b) in different solvents have been determined at temperatures in the -10 to 40 °C range. The heterogeneous epoxidation exhibits a dependence of the reaction rate on solvent polarity opposite to its homogeneous counterpart and anomalous activation parameters in n-hexane, which are interpreted in terms of the surface-promoted solvent structure at the solid-liquid interface. The results show that highly polar solvents can strongly inhibit heterogeneous reactions performed with silica-supported reagents or catalysts.